I don't think you'll find anything useful looking at "grand challenges" or other such lists. Problems get on such lists because they are hard to solve and becau

I don't think you'll find anything useful looking at "grand challenges" or other such lists. Problems get on such lists because they are hard to solve and because they require significant resources. A better approach might be to find a slightly technically backward field, learn about it in detail, and then apply modern technology to improve performance or lower cost. I remember meeting a guy, years ago, who had made a fortune inventing a new high-tech way to remove the casings from hot dogs. Finding an appropriate problem to solve is part of the problem.